class MyCircularQueue {

    private int[] elem;
    private int front;//队头下标
    private int rear;//队尾下标

    /**
     * 构造方法
     * @param k
     */
    public MyCircularQueue(int k) {
        this.elem = new int[k];
    }

    /**
     * 入队
     * @param value
     * @return
     */
    public boolean enQueue(int value) {
        if (isFull()) {
            return false;
        }
        this.elem[rear] = value;
        rear = (rear+1) % elem.length;
        return true;
    }

    /**
     * 出队
     * @return
     */
    public boolean deQueue() {
        if (isEmpty()) {
            return false;
        }
        front = (front+1) % elem.length;
        return true;
    }

    /**
     * 得到队头元素
     * @return
     */
    public int Front() {
        if (isEmpty()) {
            return -1;
        }
        return this.elem[front];
    }

    /**
     * 得到队尾元素
     * @return
     */
    public int Rear() {
        if (isEmpty()) {
            return -1;
        }
        //return this.elem[(rear+elem.length-1)% elem.length];
        int index = (rear == 0) ? (elem.length-1) : (rear-1);
        return elem[index];
    }

    /**
     * 当前循环队列是否为空
     * @return
     */
    public boolean isEmpty() {
        return rear == front;
    }

    /**
     * 判断当前队列是否为满
     * 浪费一个空间表示队列满了
     * @return
     */
    public boolean isFull() {

        if ((rear+1) % elem.length == front) {
            return true;
        }
        return false;
    }
}